Single thread sewing machine



Jan. 2, 1934. M, McClANN 1,941,481

SINGLE THREAD SEWING MACHINE Filed July 12, 1929 3 Sheets-Sheet l 1 mumIN V EN TOR. W7 WAC/9,454 M Cfl/v/v 5 ATTORNEY 3 Sheets-Sheet 2INVENTOR. Ma /6 f! We C/i/v/v ATTORNEYS.

Jan, 2, 1934. M. M CANN SINGLE THREAD SEWING MACHINE Filed July 12 1929Jan. 2, 1934. M. M CANN SINGLE THREAD SEWING MACHINE Filed July 12, 19295 Sheets-Sheet 3 IN V E TOR. Awe/4454 C'fl/v/v BY 5 I l A TTORNEYPatented Jan. 2, 1934 PATENT GFFICE SINGLE THREAD SEWING MACHINE MichaelMcCann, Glen Morris, N. Y., assignor to Frederick Osann Company, NewYork, N. Y., a corporation of New York Application July 12, 1929. SerialNo. 377,736

Claims.

My present invention relates to chain stitch or single thread sewingmachines, and particularly to button sewing machines. The general objectis to provide such a machine with improved means 5 for controlling theposition of the thread loop engaged by the revolving looper of thesewing machine while the needle is below the work, and particularlywhile the needle is descending preparatory to the formation of a newloop about which the first mentioned loop will be subsequently cast.More specifically, the object of the invention is to provide a loopdeflector or loop positioning arm or finger and operating mechanism forthe latter which are characterized by the positive and easy movements ofthe operating parts, the simplicity and ruggedness of the oper atingmechanism, its reliability in operation, and its capacity for continuousoperation at relatively high speeds.

A further object of the invention is to provide a sewing machine of thetype mentioned with a simple and effective needle guide operative toreturn the free end of the needle into proper relation with the looptaking hook when the needle has been deflected away from the hook by thework penetrated. My improved needle guide and improved loop deflectorare preferably combined in a single movable part.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its advantages and specific objects attained with its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described preferred embodimentsof my invention.

Of the drawings:-

Fig. l is an elevation with parts broken away and in section of aportion of a button sewing machine;

Fig. 2 is a section on the line 2-2 of Fig. 1;

Fig. 3 is a sectional elevation of a portion of the machine, the sectionbeing taken at right angles to Fig. 1.

Fig. 4 is a partial section on the line 4--4 of Fig. 3;

Fig. 5 is a plan view of the hook;

Fig. 6 is a plan view of a portion of the machine;

Fig. 7 is a sectional elevation showing relative positions of partsincluding the thread finger when the latter is in the position shown inFig. 6;

Figs. 8, 9, 10 and 11 are views taken similarly to Fig. 7, showingpositions successively occupied by the parts as the button sewingoperation proceeds;

Fig. 12 is a view taken similarly to Fig. 6, with 7 the parts shown inthe positions occupied by them 6 0 in Fig; 10;

Fig. 13 is an elevation taken similarly to Fig.

1, illustrating a modification of a portion of the apparatus shown inFigs. 1 and 2; and

Fig. 14 is a view taken at right angles to Fig. 13. 0B

In the drawings, A represents the bed of a button sewing machine of wellknown type comprising a cloth plate portion 13 with an elongated needleopening B for the vertically movable needle C. Above the cloth plate islocated a but- 76' ton clamp D, and beneath the cloth plate is locatedthe rotary looper E which may be of the usual type and is carried by arotating shaft e.

The shaft e is driven through the coupling ea by the driving shaft eb,and it will be understood that the latter is operatively connected inany usual or suitable manner with the means for supporting the needle Cand giving the latter its usual movements. The relative movements of theneedle and the button necessary for the successive penetration ofdiiierent holes in the button may be effected by mechanism of any usualor suitable type for the purpose. It is to be noted, however, that theloop deflecting means herein provided are of especial utility in abutton sew ing machine in which the needle is caused to successivelypenetrate difierent thread openings in the button by shifting the needleand not the button holder. It is unnecessary to illustrate and describemechanism for giving the needle its movements as the details of suchmechanism form nopart of the present invention, and mechanisms for thepurpose are well known.

In accordance with the present invention the limbs of a previouslyformed thread loop which is engaged by the looper during the descent ofthe needle through the work and the cloth plate in the formation of asecond loop to be drawn through the first mentioned loop by the looper,are positioned with respect to the path of the descending needle by aloop deflector or thread positioning arm or finger f. The latter issimilar in purpose and in the general character of its movementsparallel to the plane of looper rotation, to the loop positioning arm orfinger of 05 the prior Lyons Patents Nos. 788,213 and 856,645. The looppositioning means disclosed and claimed herein differ from the looppositioning means of said prior patents, however, in various respectscontributing to mechanical simplification, case of movement, and theavoidance of lost motion or vibration, these advantages of myimprovement being especially important in button sewing machinesintended and adapted for operation at high speed.

In accordance with the present invention, the loop positioner ordeflector f is carried by an oscillating support, which, in thepreferred construction illustrated, comprises a carrier arm F whichcurves about the looper axis and is rigidly secured to a rock shaft Glocated beneath and parallel to the shaft e. The shaft G is mounted inbearings A and A carried by the machine bed, and in which the shaft G isoscillated about its own axis to thereby give the loop deflector f itsmovements as hereinafter described. Advantageously the bearing Acomprises an elongated bearing sleeve axially adjustable in an openingin the bed, being normally secured in the desired adjustment by a setscrew A The sleeve of bearing A extends between a collar G on the shaftG and the hub of the arm F which may be adjusted in the direction of thelength of the shaft G by a corresponding adjustment of said sleeve.

The preferred mechanism shown for giving the shaft G its oscillatorymovements in proper timed relations with the movements of the needle andthe looper, comprises a cam member H mounted on the hook shaft e androtating with the latter. The cam H is caused to oscillate the shaft Gby its engagement with an arm'G. The latter is adjustably clamped to theshaft G and is held against the periphery of the cam H by a tensionspring K shown as connected at one end to the bed of the machine and atthe other end to a projection or hook G secured to the arm G. The majorportion of the periphery of the cam H is cylindrical and co-axial withthe hook shaft e, but a portion H of the cam H is cut away and shaped togive oscillatory movements to the shaft G and thereby to the threadfinger F.

For ease and definiteness of description, I shall refer to points orpositions at the right hand side of any reference point or part, as seenin Figs. 1, 6 and 12 as at the inner side of said reference point orpart, and shall refer to points or positions at the left of a referencepoint, as at the outer side of the latter. Similarly, a point orposition to the right of a reference point as seen in Figs. '7 to 11,inclusive, will be referred to as a rear or rearward point or position,and a point or position to the left of the last mentioned refence point,as seen in said figures, will be referred to as a front or forward pointor position, such use of the terms rear, rearward, front and forward,being predicated on the fact, that the beak E of the looper E moves fromthe right to the left in Figs. 7 to 11 in moving through its loopseizing position.

In the preferred construction illustrated, the thread finger 7 projectsoutwardly and forwardly from the outer side of the tip F of the carrierarm F. Advantageously, the thread finger f is made separable from thecarrier arm F and is detachably secured to the latter. This facilitatesreplacement and adjustment. As shown, the thread finger f is in the formof a curved barb projecting through an aperture in the tip end F of thearm F, and having a body portion f adjustably clamped against the innerside of the arm F by a clamping screw P.

In Figs. 6 and 7, parts are shown in the position occupied by them asthe needle is completing an initial loop forming operation with thethread loop extending through a rear thread hole 2 in a button I whichis being attached to fabric J. Figs. 8, 9 and 10 represent successivepositions of the parts during the operation of forming a loop extendingthrough a forward thread opening 2" in the button I. As the needle C-begins to descend from the position shown in Figs. 6 and '7, theadvancing thread finger engages the limbs of the thread loop thensurrounding the looper E as shown in Fig. 8, and moves the threadportions engaged forwardly. Preferably, as shown, the shape of thefinger is such that the loop portions engaged are moved inwardly as wellas forwardly.

In particular, as the needle passes downward through the work in movingfrom the position shown in Fig. 8 to that shown in Fig. 9, there is notendency for the needle to pass to the inward side of either of the looplimb portions t extending between the work and the deflecting finger 1when the latter is used. The passage of the needle between the upperloop limb portions t which may occasionally occur if no loop defiectoror a less efficient loop deflector is employed, ordinarily results in amissed stitch. This is due to the fact that when the needle, afterpassing between the loop limb portions t passes between the lowerportions t and t of the loop limbs as shown in Fig. 9, the needle thenreally passes out of the loop which is about to be cast off so that whensaid loop is'subsequently cast off, it does not surround the new loo-pthen caught on the looper beak. In addition to this major advantage, theaction of the thread finger tends to eliminate occasional thread snarlsdue to faulty thread tension, or difficulties in the sewing operationsuch as may be due to irregularities in the fabric, or in the buttonshape or disposition.

As shown in Fig. 11, the loop deflector f operatively engages anddeflects the loop about to be penetrated by the needle, when that loopextends downward from the front thread hole opening 2" in the button I.Those skilled in the art will understand, however, that the practicaladvantages of the loop deflecting means shown are largely confined tothe operations in which the loop engaged by the thread finger extendsdownward from a rear buttonthread opening 2. This is in large part dueto the disposition of the portions of the limb of the loop then betweenthe loop deflecting finger and the work, but is in part due, also to therelative increase in looper speed which occurs in the operation of thestandard forms of chain stitch mechanisms having the usual coupling eabetween the shafts eh and e, as the looper turns from the position shownin Fig. 9 into the position shown in Fig. 10.

Advantageously, though not necessarily, the front end of the elongatedneedle opening B in the cioth plate B as shown in Figs. 6 to 12, islaterally enlarged at its inner side. The enlargement B provides aclearance space for the portion of the thread loop between the threadfinger f and the work when the thread loop engaged by the finger 1extends through the front button thread opening 2'.

A characteristic advantage of the loop deflector mechanism disclosed isthat the simple outwardly and forwardly extending finger f not onlydeflects the loop operatively engaged forwardly and 1 1.

inwardly against the back wall of the thread opening when the threadfinger moves forwardly from the position shown in Fig. 7 into that shownin Fig. 10, but when, on the return stroke of the thread finger from theposition shown in Fig. 10

back to the position shown in Fig. 7', the thread finger f engages theloop then: caught on the looper, the loop so engaged is harmlesslybrushed aside.

The present invention is of especial utility, as previously pointed out,in sewing machines like that shown in said Patent No. 788,213, in whichthe button is held stationary, and the needle is automatically shiftedas required for the penetration of the different thread openings in thebutton. The invention is not without utility, however, in machines likethat shown in said Patent No. 856,645 in which the normal needlemovement is in a straight line, and in which the button is shifted topresent first one and then another thread opening to the needle. Whilein such case the positions of the needle and the looper are always thesame when a loop is taken on the looper beak E, except as the needle maybe strained from its normal position by the work, the upper end of theloop engaged by the looper is nevertheless alternately in front, and atthe rear of the needle, and when at the rear of the needle there is anobjectionable tendency toward an improper penetration of the loop by theneedle.

Advantageously and as shown, the thread finger arm F is provided with abranch or tine F having a needle guide surface which extendssubstantially parallel to the length of the needle slot B and whichextends forwardly from the normal needle position when the latter isdescending into proximity with the looper. The needle guide surface isbeveled off as shown in Fig. 3, and serves to deflect the needleinwardly into proper position relative to the looper E, whenever as mayoccasionally occur, the needle is deflected by the work forwardly of itsnormal position. This eliminates or greatly minimizes occasional stitchformation failures otherwise experienced from the failure of the looperhook to pass between the needle and the thread passing to the eye of theneedle from the work. With the elongation of the needle guide surfaceshown, said surface is equally effective whether the needle is passingthrough the front or rear button thread opening 1', or i, of a machinein which the needle is shifted to penetrate difierent thread openings.

The character of the loop deflecting and loop guiding provisionsillustrated and described permits the thread finger and its supportingprovisions to be made strong and rigid, and to have easy movements withan avoidance of lost motion, so that little or no difliculty fromvibration or lost motion is experienced in operation at high speed. Thefact that the shaft G is located below the shaft 6 and hence at aconsiderable radial distance from the deflecting finger 1, permits thelatter to be given operative movement of ample extent by a relativelysmall angular movement of the shaft G, and said operative movements ofthe finger f therefore depart but little from the horizontal movementsof the loop deflecting finger obtained with the mechanisms of said priorpatents. The mechanical simplicity and ruggedness of the constructionalso contribute to successful high speed operation since there ispractically nothing to get out of order or to require especial carefuladjustment.

In the modification shown in Figs. 13 and 14, the simple cam H andspring pressed follower G of Figs. 1 and 2, are replaced by a compoundcam HA, adjustably secured on the shaft e, as by a set screw H andhaving two axially displaced cam portions HA and HB. The cam portion HAmay be similar in shape to: the cam of the con.- struction firstdescribed, and; is engaged: by a lever arm GA adjustably secured. to therockshaft G. The lever GA and cam part HA give the thread deflector itsmovements in one, direction. The movements in the return directionimparted to the rock shaft G inthe construction first described by thespring K, are impartedto. the rock shaft in the construction shown inFigs. 1:31 and 14, by a cam follower lever arm GB adjustably secured tothe shaft G and engaging the cam part H3. The arrangement shown in:Figs. 13: and 14 is easier to adjust and somewhat more positive in itsaction than the arrangement shown Figs. 1 and 2.

While in accordance with the prosisions of the statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed withoutdeparting from the spirit of my invention as set forth in the appendedclaims and that in some cases certain features of my invention may beused to advantage without a corresponding use of other features.

Having now described my invention what I claim as new and desire tosecure by Letters Paten 1s:

1. In a single thread sewing machine, the combination with a looper andits supporting shaft, of a rock shaft parallel to the looper shaft andat the opposite side of the latter from the work, an arm secured at oneend to said rock shaft and provided at its other end with a needle guidesurface and with a loop deflecting part, said surface and part beingmoved between the looper and the work when said rock shaft isoscillated.

2. In a single thread sewing machine, the combination with areciprocating needle, a looper shaft, a looper carried by said shaft andcontinuously rotated in the same plane by said shaft to successivelyseize, expand and cast-off chain stitch needle thread loops, a loopdeflecting member restrained against movement transversely of said planebut movable parallel to said plane between the looper and the work toengage the limbs of a needle loop on the looper and move the same out ofthe path of the needle, and means for operating said member comprising arock shaft operatively connected to said member and arranged parallel tosaid looper shaft and at the opposite side of said looper from the work.

3. In a single thread sewing machine, the combination with areciprocating needle, of a looper shaft, a looper carried by said shaftand. continuously rotated in the same plane by said shaft tosuccessively seize, expand and cast-off chain stitch needle threadloops, a loop deflecting member restrained against movement transverselyof said plane but movable parallel to said plane between the looper andthe work to engage the limbs of a needle loop on the looper and move thesame forwardly out of the path of the needle, and means for operatingsaid member comprising a rock shaft to which said member is secured,said rock shaft being arranged parallel to said looper shaft and at theopposite side of said looper from the work, and a carrier arm secured tosaid shaft and curving about the looper axis, said member being mountedon the free end of said arm.

4. In a single thread sewing machine, the combination with areciprocating needle, of a looper shaft, a looper carried by said shaftand continuously rotated in the same plane by said shaft to successivelyseize, expand and cast-off chain stitch needle thread loops, a loopdeflecting member restrained against movement transversely of said planebut movable parallel to said plane above the looper to engage the limbsof a needle loop on the looper and move the same forwardly out of thepath of the needle, and means for operating said member comprising anoscillatable rock shaft to which said member is secured, said rock shaftbeing arranged parallel to said looper shaft and at the opposite side ofsaid looper from the loop engaging portion of said member, a cam carriedby said looper shaft at the inner side of said looper, and an armengaging said cam and secured to said rock shaft.

5. In a single thread sewing machine, the combination with areciprocating needle, of a looper shaft, a looper carried by said shaftand continuously rotated in the same plane by said shaft to successivelyseize, expand and cast-off chain stitch needle thread loops, a loopdeflecting member restrained against movement transversely of said planebut movable parallel to said plane above the looper to engage the limbsof a needle loop on the looper and shaped to move the same when engagedinwardly and forwardly out of the path of the needle, and means foroperating said member comprising an oscillatable rock shaft to whichsaid member is secured, said rock shaft being arranged parallel to saidlooper shaft and at the opposite side of said looper from the loopengaging portion of said member.

MICHAEL MCCANN.

